This disclosure relates to alloy compositions and, more particularly, to a nickel alloy composition that provides enhanced environmental resistance.
Nickel braze alloys are commonly used for abradable coatings on nickel alloy substrates, such as gas turbine engine components. For example, nickel braze alloys used as original coatings or for coating repair may include a mixture of a high melting point nickel alloy and a lower melting point nickel alloy having a different composition. The nickel braze alloy may be applied in a repair process to worn and/or damaged areas of the substrate and then heated to a brazing temperature to wet the surfaces and flow into any pores or cracks. Upon cooling, the nickel braze alloy forms a composition that is a combination of the high melting point nickel alloy and the lower melting point nickel alloy.
One drawback of at least some known nickel braze alloys is reduced environmental resistance compared to the nickel alloy substrate. For instance, the nickel alloy of the substrate forms an oxide scale that functions as an oxygen barrier to protect the underlying nickel alloy substrate from corrosion. However, the different composition of the nickel braze alloy may form an oxide scale that is unstable or prone to spalling. Consequently, the nickel braze alloy may not be capable of providing a substantially equivalent degree of corrosion protection as the nickel alloy substrate.